The Visa Waiver Program Improvement and Terrorist Travel Prevention Act of 2015, added to the omnibus before its enactment in December 2015, tightened security restrictions on those traveling through the VWP by blocking participation by foreign nationals who have visited Iraq, Syria, Iran, or Sudan within the last five years—requiring those individuals instead to go through the longer process of obtaining a visa.

But it also prohibits nationals of participating VWP countries who would otherwise be eligible for the VWP from participating if they happen to be dual nationals of one of those four nations, even if they haven’t recently traveled to one of the restricted countries. This could be especially problematic for dual nationals of countries like Iran and Syria that pass on citizenship from the father, making it possible for someone to be a Syrian or Iranian national without ever having stepped foot in the country.

The restrictions could directly impact American citizens and other nationals because the VWP is based on reciprocity. If the United States discriminates against Europeans who are dual nationals, these partner countries are likely to reciprocate and enact similar restrictions on Americans. Prior to the vote on this language, ambassadors from 28 European member states—23 of which currently participate in the VWP—authored an op-ed warning Congress of exactly such legally mandated reciprocal measures.

“Without EPTA, the recently enacted visa law could harm countless Americans—even United States-born citizens—who have limited or indirect connections to countries of concern,” said Amash. “It’s not okay to subject Americans to different standards for travel on the basis of ancestry.”

“The most fundamental responsibility of government is to keep the American people safe,” said Dingell. “Strengthening the Visa Waiver Program is vital to meeting that goal, but provisions in December’s government spending bill unfairly target individuals of certain nationalities. Individuals seeking to enter the United States should be evaluated based on the specific security threat they pose. I look forward to working with my colleagues to ensure our laws judge people based on the content of their character.”